Apparatus for Placing Battery Plates

ABSTRACT

This invention relates to apparatus for placing battery plates in a line from a stack of plates including an elevator for receiving a stack of plates and sequentially elevating the stack to maintain, in use, the uppermost plate in the stack in a datum region lying between two parallel generally horizontal planes and a plurality of vacuum heads arranged in a closed loop for sequentially passing over the elevator with a fixed gap from the upper plane of the datum range for picking up the uppermost plate and for subsequently releasing the plate at a release position.

FIELD OF THE INVENTION

This invention relates to an apparatus for placing battery plates in aline from one or more stacks of plates.

BACKGROUND OF THE INVENTION

It is well known, during the manufacture of batteries containing batteryplates to have to take battery plates from stacks, formed when thebatteries are moulded, and to lay them into a line for subsequenthandling, when they are formed into groups with separators and properlyorientated terminals. In recent years many parts of the assembly linehave been speeded up and there is a need for apparatus which can performthis function at high speed. With this in mind, arrangements such as areillustrated in U.S. Pat. Nos. 4,784,380 and 6,971,838 have beendeveloped where multiple in line heads pick up battery plates fromrespective stacks and then deliver them onto a conveyor. By mountingthese heads in line on a rocking or translatable carrier five or soplates can be deposited simultaneously, in line, on a conveyor. Thesesystems have been found to have speed limitations, which do not enablethem to meet the requirements of a modern line.

A further problem, which is recognised in U.S. Pat. No. 6,971,838,arises from the porous nature of many plates which now need to behandled and the need to ensure that only one plate is being picked up ata time.

BRIEF SUMMARY OF THE DISCLOSURE

From one aspect the invention consists of an apparatus for placingbattery plates in a line from a stack of plates, including an elevatorfor receiving a stack of plates and sequentially elevating the stack tomaintain, in use, the uppermost plate in the stack in a datum rangelying between two parallel generally horizontal planes and a pluralityof vacuum heads for sequentially passing over the elevator with a fixedgap from the upper plane of the datum range for picking up the uppermostplate and for subsequently releasing the plate at a release position.

The applicants have realised that, surprisingly, they can createapparatus capable of much higher speeds from a single stack, rather thantaking the plates from a multiplicity of in line stacks. This is becausewith the vacuum heads arranged in a loop there is not the samerequirement for acceleration and deceleration as occurs in the earlierdesign. Further, by having an elevator which places the uppermost platein a predetermined datum region, the geometry of the relationshipbetween the position of the plate and the vacuum head can beparticularly simply designed, with the result that no contact isrequired between the plate and the vacuum head. This prevents damage tothe plates which can occur if a plate is drawn across the top of the onebeneath it as has been seen with other plate handling systems that wipethe plates from the stack.

In a preferred embodiment the apparatus further includes a carrierrotatable about a generally vertical axis, in which case the vacuumheads may be mounted on the carrier and spaced around the axis.

There may be an evacuable plenum, which may also be mounted on thecarrier, and in this case each vacuum head may be connectable to theplenum by a respective valve. A control may be provided for opening avalve associated with a head as the head approaches the elevator and forclosing the valve when the head is in the release position.

Conveniently an output conveyor extends beneath the release position forreceiving the release plates.

An input conveyor for delivering stacks of plates to the elevator mayalso be provided.

There may be a plurality of elevators moveable between an inactiveposition where a stack can be received and an active position.Conveniently there can be two elevators arranged diametrically relativeto the axis, in which case the apparatus includes an input conveyorextending along the diameter. The apparatus may further include aturntable for rotating a stack before it is fed to one of the conveyorsand preferably that one conveyor is the most downstream conveyor.Conveniently an elevator can perform the role of a turntable.

This turntable enables the stacks to be orientated in an appropriateposition for their elevator so that, when released, the plates in theline have a common orientation.

From another aspect the invention consists in apparatus for placingbattery plates in a line from stacks of plates including a plurality ofvacuum heads for picking up, in a pick-up position a top most plate froma stack and subsequently releasing it at a release position and acarrier for carrying the heads and moving them between the pick-up andrelease positions, wherein in the pick-up position there is a space, inuse, between the uppermost plate and the associated vacuum head, wherebythe plates moves to the head.

Although the invention has been defined above it is to be understoodthat it includes any inventive combination of the features set out aboveor in the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be performed in various ways and a specific embodimentwill now be described, by way of example with reference to theaccompanying drawings in which:

FIG. 1 is a plan view of apparatus for placing battery plates in a linefrom a stack of plates:

FIG. 2 is a view of the apparatus of FIG. 1 on the Arrow A; and

FIG. 3 is an end view of the apparatus in the direction B;

FIG. 4 is a schematic view from above of the carrier of the apparatus ofFIG. 1;

FIGS. 5( a) to 5(f) and 5(i) to 5(o) indicate a supply sequence to thecarrier of FIG. 4 and;

FIGS. 6( a) and (b) are respective side and front views of an elevatorlocation.

DETAILED DESCRIPTION OF THE DISCLOSURE

Referring to FIGS. 1 to 3, apparatus generally indicated at 10, isprovided for taking plates 11 from a stack 12 and depositing themsequentially in line on a conveyor 13. The apparatus 10 includes acarrier 14 rotatable about a vertically extending axis 15, which carriesa number of vacuum heads 16, which are spaced circumferentially aroundthe carrier 14. The carrier also carries a box 17 that defines anevacuable plenum 18, which is on the one hand connected to a vacuumsource (not shown) and on the other hand communicates with respectiveheads 16 via tubes 19 that are open and closed by respective butterflyvalves, one of which is shown at 20. The valves 20 can be moved betweenopen and closed positions, for example by the ram 21 and toggle actuator22. A motor 24, is provided for rotating the carrier on a shaft 23 inthe direction of the Arrow C by means of a pulley 24 a and belt 25.

As can be seen in FIG. 3 the stack 12 is mounted on an elevator 26,which can be raised and lowered by means of a rack and pinionarrangement indicated at 27.

In its simplest form of operation, the carrier 14 is rotated and as aparticular head 16 approaches the elevator 26, its butterfly valve 20 isopened connecting the head 16 to the source of vacuum by means of theplenum 18. As the “on” head 16 passes over the uppermost plate 11 in thestack it lifts the plate onto the vacuum head 16 whereupon it iscarried, from this pick-up position over the elevator 26 to a releaseposition over the conveyor 13. At that point the butterfly valve 20 isclosed, removing the vacuum and releasing the plate 11 to drop onto theconveyor 13.

It is preferred, particularly when porous plates have been handled, thatthe mouth 28 is relatively large and the vacuum source and plenum arearranged so as to encourage fairly high air flow, but low vacuum. Thisis because as ingressing air sweeps across the surface of the uppermostplate it tends to cause an aerodynamic lift separating the uppermostplate from the stack, and enabling it to be captured by a low vacuum andreducing the chance of more than one plate 11 being picked up at once.

Because the carrier 14 is constantly rotating, without any need fordeceleration, it can be rotated at high speeds, with the result that,even though only one plate is being picked up at a time, plates can bedelivered onto the conveyor at rates at least up to 200 plates perminute.

It will be understood that in order to benefit significantly from suchhigh delivery rates, it is desirable to have a system for replenishingthe stack as quickly as possible. The applicants have arranged for thisconveniently by providing a second elevator 29, which is locateddiametrically opposite the first elevator 12, so that whilst oneelevator is in an active position from which plates can be picked up,the other elevator can be in an inactive position in which it canreceive a fresh stack of plates. Because the elevators 26 and 29 areopposite each other, it is necessary to ensure that the stacks providedare orientated so that the stacks provided to one elevator are 180°rotated as compared with those provide to the other elevator. This canbe achieved in a number of ways one of which is illustrated in thedrawings. Here a conveyor system generally indicated at 31 brings stacks12 sequentially to a turntable 32 that can be elevated through the planeof the conveyor system 31 to temporarily retain a stack 12 and, ifnecessary rotate it.

If elevator 12 is in the active position and plates are being removedfrom it, then elevator 30 should be in its inactive lowered positionbeneath the plane of the conveyor system 31. The turntable 32 will thenrotate through 180° a first stack that it has received, lower those backonto the conveyor system 31 so that they are fed into a buffer position33, beneath the shaft 23. As it will be noted that the conveyor system31 is formed by two aligned conveyors 34 and 35. It will be understoodthat the rotated stack 12 a can be retained in the buffer position bypausing the conveyor 34. The turntable 32 can then either stay loweredand simply allow the next stack to pass onto the elevator 30, which cancapture the stack by passing up through the plane of the conveyor system31 or it can retain it temporarily so that it can release the stack withposition timing to meet the elevator 32 as it rises. When the elevator26 has been emptied, the elevator 30 then rises up into its activeposition and plates are picked up from there so that there is no gap inthe provision of the plates. It may be desirable to adjust therotational speed of the carrier at least momentarily, because theelevator 30 is a shorter distance from the conveyor 13 than the elevator12 and it will usually be desirable for there to be equal spacingbetween the plates 11. A similar effect could be achieved by varying thespeed of the conveyor 13.

A control 36 is provided for controlling the motor, the valves and thevarious conveyors and elevators in accordance with the operationalprotocol described above. A means of controlling such elements would bewell understood by one skilled in the art.

Variations on this design are described with reference FIGS. 4 to 6.FIGS. 4 and 5 show an arrangement, which deals with a problem that canarise using the previously described apparatus. As proposed in thatapparatus plates are initially picked up by the nozzle 16 which is inpick up position A and when the associated stack 12 is used up the pickup or nozzle at 16 at position B begins to lift plates 11 from itsassociated stack 12. It has been found that if one waits until the lastplate is lifted from elevator 26 before lifting elevator 29, then aspace tends to occur between plates laid on out feed conveyor 13 becausethe nozzle instantaneously lying between A and B, which has passed overan empty stack, arrives at B before a plate is ready to pick up.

FIGS. 5( a) to 5(f) and 5(i) to 5(o) show a sequence of plate feeding,which overcomes this problem and introduces a slightly differentapproach to the alignment of lugs issue. Looking at FIG. 5( a) first, itwill be noted that pick up positions A and B have respective sensors37,38 for detecting the presence or absence of a plate 11 in the datumregion from which a plate is picked up. The sensors 37,38, which aretypically lasers that can be reflected in the absence of a plate in thedatum region, are connected to the control 36 and in particular are usedto control respective elevators 26 and 29. A further, double sized,elevator 40 is provided upstream of the elevator 29 in association withthe feed conveyor 31.

Thus in FIG. 5( a) stacks 1 and 2 have been moved onto the elevator 40by the in feed conveyor 31 and can be retained in that position by theelevator 40 lifting them clear of the conveyor 31. In FIG. 5( b) thestacks have been released by the conveyor 40 and moved downstream. Stack2 lies above the elevator 29 and can be captured in that position by theelevator 29 lifting it clear of the conveyor bed. This can be seen inFIG. 5( c). The stack 1 has now reached elevator 26, which in thisembodiment is configured as a turntable. Elevator 26 rotates the stackso that the lugs on the plates 11 will be suitably orientated and in themeantime further stacks 3 and 4 are delivered onto the elevator 40. InFIG. 5( d) elevator 26 lifts stack 1 so that plates are removed one byone, as previously described from stack 1, and released onto theconveyor 13. The sensor 37 detects the presence or absence of the topplate and controls the advancement of the elevator 26. In the meantimestack 2 has been released by elevator 29 to move into a buffer positionintermediate elevators 26 and 29 and stack 3 has moved to a position inwhich it can be captured by the elevator 29.

It can be seen in FIG. 5( e) that the majority of the plates have nowbeen removed from stack 1, but at this time stack 3 is elevated so thatplates can be taken from it by a pick up in position B. In this way thatstack is ready for having plates removed before stack 1 is finished,i.e. both elevators are in an active position for an overlap period. Bysuitably controlling the valves on the pick up heads or nozzles 16, acontinuous stream of plates can be achieved.

In FIG. 5( f) stack 3 is now producing all of the plates to be passed onto the conveyor 13, whilst empty elevator 26 descends and returns to itsoriginal rotational orientation. As can be seen in FIG. 5( i) stack 2then feeds onto elevator 26 and is rotated at FIG. 5( j). In FIG. 5( k)stack 2 is now elevated by elevator 26, because it is detected thatstack 3 has been substantially used up. At FIG. 5( l) stack 2 has takenover as the feed stack and at FIG. 5( m) stacks 4 and 5 are being usedto replenish. By FIG. 5( o) the apparatus has sequenced so that itcorresponds with FIG. 5( e).

It will thus be seen that this approach handles both the issue of lugorientation and providing a continuous uninterrupted supply of plates tothe conveyor 13.

FIG. 6 shows an additional improvement which can be made. This is theprovision of a stop plate 41 which can retain the stack 12 against anywiping drag, as the top plate 11 is removed. A vertical partial notch 42is provided to allow the sensor to detect the presence or absence ofplates.

Finally, it has been found, from the control point of view, that it isparticularly efficacious to control the valves via one or more servermotors.

It will be appreciated that the design could be varied in a number ofother ways while still achieving the broad benefits of the invention.Thus the vacuum heads could be mounted on a chain conveyor or the likeand do not necessarily have to follow a circular path. However, the useof a circular carrier enables the applicant to achieve a particularlysmall foot-point compared, for example, with the in-line machinesmentioned in the acknowledged prior art. The elevators could beindividually fed laterally and the turntable could be in the bufferposition, rather than the position in which it is described. Theinvention thus covers any such variations or others clear to a personskilled in the art which fall within the scope of the attached claims.

1. Apparatus for placing battery plates in a line from a stack of platesincluding an elevator for receiving a stack of plates and sequentiallyelevating the stack to maintain, in use, the uppermost plate in thestack in a datum region lying between two parallel generally horizontalplanes and a plurality of vacuum heads arranged in a closed loop forsequentially passing over the elevator with a fixed gap from the upperplane of the datum range for picking up the uppermost plate and forsubsequently releasing the plate at a release position.
 2. Apparatus asclaimed in claim 1 further including a carrier rotatable about agenerally vertical axis and wherein the vacuum heads are mounted on thecarrier and spaced around the axis.
 3. Apparatus as claimed in claim 2further including an evacuable plenum and wherein each vacuum head isconnectable to the plenum by a respective valve.
 4. Apparatus as claimedin claim 3 further including a control for opening a valve, associatedwith a head, as the head approaches the elevator and for closing thevalve when the head is the release position.
 5. Apparatus as claimed inclaim 1 including an output conveyor extending beneath the releaseposition.
 6. Apparatus as claimed in claim 1 including an input conveyorfor delivering stacks of plates to the elevator.
 7. Apparatus as claimedin claim 1 including a plurality of elevators moveable between aninactive position and an active position.
 8. Apparatus as claimed inclaim 7 wherein only one elevator can be in an active position at anyone time.
 9. Apparatus as claimed in claim 2 wherein there are twoelevators moveable between an inactive position and an active position,the two elevators arranged diametrically relative to the axis and theapparatus including an input conveyor extending along the diameter ofthe carrier.
 10. Apparatus as claimed in claim 7 wherein two elevatorscan be active during an overlap period.
 11. Apparatus as claimed inclaim 10 wherein there are two input elevators arranged diametricallyrelative to a vertical axis and the apparatus including an inputconveyor extending along the axis.
 12. Apparatus as claimed in claim 7including at least one buffer elevator for temporarily halting travel ofa stack along an input conveyor.
 13. Apparatus as claimed in claim 1further including a turntable for rotating a stack.
 14. Apparatus asclaimed in claim 13 wherein the turntable is an elevator.
 15. Apparatusas claimed in claim 10 wherein the one conveyor is the most downstreamconveyor.
 16. Apparatus for placing battery plates in a line from stacksof plates including a plurality of vacuum heads for picking up, in apick-up position, a topmost plate from a stack and subsequentlyreleasing it at a release position and a carrier for carrying the headsand moving them between the pick-up and release positions, wherein inthe pick-up position there is a space, in use, between the uppermostplate and the associated vacuum head whereby the plate moves to thehead.
 17. Apparatus as claimed in claim 16 wherein the valves arecontrolled by a servomotor.